This is a collections of gameplay clips from the source code leak of October 2003 - These are the original leak files, which I found on an old backup DVD.
As you can see the game is quite rough, but it does resemble the HL2 that we know today. I've included comparisons of levels that made it to release, and some that didn't.
Towards the end of the video, the last clip shows an interesting aspect of the plot/storyline between Half-Life and Portal.
